fn is_mutex_lock_call<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option<&'tcx Expr<'tcx>> {
if_chain! {
if let ExprKind::MethodCall(path, _span, args, _) = &expr.kind;
fn is_mutex_lock_call<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option<&'tcx Expr<'tcx>> {
if_chain! {
if let ExprKind::MethodCall(path, _span, args, _) = &expr.kind;